sounds pretty darn weird to me..
have you checked other companies who do the Iguazu falls tours? Like defrantur or even port compass?
De Frantur is all over the place in Buenos Aires ( I mean their tour guides were ) and they have a great reputation. Would contact them and see what they say. I know some companies will expect payment if plane fare is needed but how they collect it is another story. The one you are getting sounds weird Marcie.
http://www.defrantur.com/ingles/
